Originally they used 'Stripes' however this was changed to the current 'Go Cat'.
Callsigns are a pain to manage for international airlines (and Tiger use the same callsign for the entire group so Singapore and Australian operations). The callsign mustn't conflict with or cause confusion on a global scale for approved ICAO callsigns!
Case in point V Australia:
ICAO code is VAU,
Originally was 'Kanga' however was then asked to be changed (presumably because internationals would get confused when told to "Follow the KANGA" they'd follow the nearest Qantas aircraft!).
Then changed to 'Vee Oz' which is what it is now. However this has been asked to be changed
again because this is confusing in Australian airspace where Virgin Blue uses ICAO code VOZ but the callsign 'Virgin'. You can see the potential for a slip-up! I don't know what the next one will be or when it will change but 'Velocity' has been rumoured.
GO CAT is a brand of cat food here and in the UK....
www.go-cat.co.uk/
Needless to say there were a few 'Meow' noises on freqencies the first few days!
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